Critical illness-related corticosteroid insufficiency (CIRCI) in dogs with systemic inflammatory response syndrome (SIRS)

Critical illness-related corticosteroid insufficiency (CIRCI) is an inade- quate corticosteroid activity in relation to the patient's current degree of stress or illness. CIRCI occurs in 30-60% of critically-ill human patients and up to 48% of dogs with sepsis. This study investigated the frequency of CIRCI in systemic inflamma- tory response syndrome (SIRS) dogs and associations between CIRCI and hypotension and mortality. A single-center prospective study was performed between December 2016 and May 2017 (ethical approval n63 711/2016). SIRS was diag- nosed if dogs presented at least two of the following criteria at the admission in ICU: 1) rectal temperature > 39.0C or < 38.0C; 2) heart rate > 120 bpm; 3) respiratory rate > 20 bpm; 4) white blood cells <6 x 103/μL or > 16 x 103/μL or > 3% of band neutrophils. Dogs were excluded if they have a history of or suspected adrenal illness or if they received glucocorticoids within the previous 72 hours or long acting formulations within the previous month or other drugs known to affect the hypothalamic-pituitary-adrenal axis. ACTH stimulation test was performed in all dogs immediately after inclusion in the study and dogs with a Δ cortisol (difference between post-ACTH stim- ulation and basal cortisol) ≤3 μg/dL supported diagnosis of CIRCI. Non- invasive blood pressure (petMAPTMgraphic II, Ramsey Medical) was mea- sured in all dogs and hypotension was defined as a mean arterial pressure (MAP) <60 mmHg. Information about survival at 28 days after admission were collected. Dogs were divided into survivors and non-survivors. Dogs that were euthanized for financial reasons were excluded. D'Agostino-Pear- son's test tested data for normality. Age, basal cortisol and MAP were com- pared between dogs with or without CIRCI. Δ cortisol, basal cortisol and MAP were compared between survivors and non-survivors using t-test. Association between CIRCI, hypotension and mortality were evaluated with Fisher's exact test. For all analyses, a P-value ≤0.05 was considered significant. Twenty-one dogs met the inclusion criteria and were enrolled in the study. CIRCI and hypotension was detected in 10/21 (48%) and 7/21 (33%) dogs, respectively. Age, MAP, basal cortisol and hypotension were similar between dogs with or without CIRCI. 14/21 dogs (67%) died within 28days from admission. As independent factor,hypotension and basal hypercortisolemia were associated with higher risk of death (P = 0.04 and P = 0.0251, respectively). CIRCI seems to occur frequently in SIRS dogs. However, only pres- ence of hypotension or basal hypercortisolemia was associated with increased mortality risk